I am primarily a libertarian for philosophical reasons. This wasn't always the case. My ascent into libertarianism began with a study of economics. It began with the columns of Walter Williams. He frequently gives an economics lesson woven within his commentary on current events. I read almost every one of his columns available in his archive. I soon discovered his "Economics for the Citizen" series, a concise introduction to several principles of economics.
From here, I discovered Thomas Sowell, a close friend of Williams. His "Basic Economics" was the first book I purchased on economics. (I've since purchased several of his books.) It taught me all about supply and demand, and why price floors and price ceilings have negative unintended (supposedly) consequences in an economy. I understood, from an economics point of view, the disaster that is government interference with voluntary trading among people, ie. "the market".
I soon discovered the Austrian School of economics. I've read Walter Block, Henry Hazlitt, Robert Murphy, Thomas Woods, and Murray Rothbard. I've learned all about praxeology, or the study of human action. From basic logical axioms, one can not only explain why government interference in the market hampers or destroys economic progress, but why only voluntary trade and social cooperation can produce prosperity.
And there you have it. Prosperity is the by-product of freedom. True prosperity, the generation of wealth, everyone's economic condition improving, can only be achieved through freedom, or through voluntary trade and social cooperation. It cannot be achieved by force. It cannot be achieved by government.
What I discovered first was that government interference in the market was bad for economic reasons. Thus I was a libertarian for economic, or consequentialist reasons. Later, I came to the belief that government interference in the market was bad for philosophical and moral reasons. Two approaches, one conclusion. What I've discovered on both paths are complimentary. That's what truth is. Truth cannot contradict truth. The libertarian political philosophy is true and good. Freedom is the only path to true prosperity.